Inorganic binders for molding and/or casting compounds have the advantage over organic binders in that they are fire resistant. Obviously inorganic binders do not contribute fuel or produce smoke when they are subjected to fire, and in the case of hydrates, undergo dehydration to provide a cooling effect which makes the hydrates good fire proofing materials.
A number of inorganic binder systems have been known to be capable of producing moldable or castable materials in that they have suitable strengths and can be caused to set up in molds in setting times comparable to the setting times of organic resins. Most of the inorganic materials which are candidates for molding compounds involve hydration with water during the setting process. One of the principal reasons, however, why such inorganic materials have never had the acceptance that organic resins have had for binders is that there has been no acceptable way for preventing the setting process from going to completion once water is added to the cement. In the case of organic resins, such as the phenolics, polyesters, epoxys, polyurethanes, etc., the setting of the organic resin is accomplished in two stages. The first stage may utilize one polymerization mechanism, while the second stage employs a different polymerization mechanism. Such control in organic systems is well known but does not exist with hydratable inorganic binders.
An object of the present invention is the provision of a new and improved process for making molded or cast parts of hydratable inorganic binders, which process will permit extended periods of time to occur between the time that the moldable or castable compound is made and the molded or cast parts are produced.
A still further object of the present invention is the provision of new and improved forms of molding compounds having hydratable inorganic binders.
Further objects and advantages of the invention will become apparent to those skilled in the art to which the invention relates from the following disclosure of applicant's preferred embodiments.